Recurrence relation running time

im having troubles to analyze Recurrence relation running time that has 2 recurrences.
now its with this relation, and i need to find it running time:
$$T(1)=1, T(n)= T(2n/3)+T(n/4)+n$$
tried several ways,such as master theorm and try to build a recursive tree, but it didnt work out.
how do i solve this and what is the correct way to approach it?
thank u in advance.